Electric power supplying device for an endoscope

ABSTRACT

Electric power supplying device for an endoscope having a photographing device, a lamp for illuminating an object for observation and a lamp for illuminating the object for photographing. The device is adoptable to an automatic exposure control type having a photoelectric element and an endoscope of the manual exposure control type. The electric power supplying device has an exposure control device, a first, a second and a third relay. When an endoscope of the automatic exposure control type is connected, the observation lamp is energized and the photoelectric element is connected to the exposure control device and, upon actuation of release means of the endoscope, the first relay is energized to actuate a switching circuit so as to energize the photographing lamp and the exposure control device supplied with the output of the photoelectric element actuates the switching circuit to terminate the energization of the lamp. When an endoscope of the manual exposure control type is connected, the observation lamp is energized and, upon actuation of the release means, the second and the third relay are actuated so as to connect an electric source of adjustable voltage to the exposure control device so that a reference voltage manually set in the source is supplied to the exposure control device while the first relay is actuated by the third relay to actuate the switching circuit so as to energize the photographing lamp which is deenergized after a time period corresponding to the reference voltage by the actuation of the switching circuit controlled by the exposure control circuit.

United States Patent Kosaka is 3,670,722 [451 June 20, 1972 [541ELECTRIC POWER SUPPLYING DEVICE FOR AN ENDOSCOPE Shinya Kosaka, Tokyo,Japan [73] Assignee: Olympus Optical Co., Ltd., Tokyo, Japan [22] Filed:Aug. 17, 1970 21 Appl. No.: 64,513

[72] Inventor:

Primary Examiner-Channing L. Pace AttameyKelman and Herman 57 ABSTRACTElectric power supplying device for an endoscope having a photographingdevice, a lamp for illuminating an object for observation and a lamp forilluminating the object for photographing. The device is adoptable to anautomatic expo sure control type having a photoelectric element and anendoscope of the manual exposure control type. The electric powersupplying device has an exposure control device, a first, a second and athird relay. When an endoscope of the automatic exposure control type isconnected, the observation lamp is energized and the photoelectricelement is connected to the exposure control device and, upon actuationof release means of the endoscope, the first relay is energized toactuate a switching circuit so as to energize the photographing lamp andthe exposure control device supplied with the output of thephotoelectric element actuates the switching circuit to terminate theenergization of the lamp. When an endoscope of the manual exposurecontrol type is connected, the observation lamp is energized and, uponactuation of the release means, the second and the third relay areactuated so as to connect an electric source of adjustable voltage tothe exposure control device so that a reference voltage manually set inthe source is supplied to the exposure control device while the firstrelay is actuated by the third relay to actuate the switching circuit soas to energize the photographing lamp which is deenergized after a timeperiod corresponding to the reference voltage by the actuation of theswitching circuit controlled by the exposure control circuit.

8 Claims, 10 Drawing Figures PATENTEDJum I972 3.670.722

sum 70F 7 INVENTOR Shmyg KOSakQ ELECTRIC POWER SUPPLYING DEVICE FOR ANENDOSCOPE BACKGROUND OF THE INVENTION The present invention relates toan electric power supplying device for an endoscope having aphotographing device and more particularly to an electric powersupplying device commonly usable with an endoscope having aphotographing device of the automatic control type and an endoscopehaving a photographic device of the manual exposure control type.

l-leretofore, an electric power supplying device has been constructedfor use exclusively with the particular type of an endoscope such as anendoscope of the automatic exposure control type having a photoelectricelement or an endoscope of the manual exposure control type, and theelectric power supplying device can not be used commonly with thedifferent types of the endoscopes, thereby making it expensive whenvarious types of endoscopes are used.

In a prior art endoscope of the automatic exposure control type, theexposure time is automatically determined by the automatic exposurecontrol device in the electric power supplying device receiving theoutput of the photoelectric element in the endoscope, and a manualcontrol of the exposure time can not be effected.

On the other hand, in a prior art electric power supplying device for anendoscope of the automatic exposure control type having a photographingdevice, the automatic exposure control device incorporated in theelectric power supplying device can not be adapted commonly to differenttypes of the films or the different types of endoscopes such as agastrocamera, an esophagocamera, a bronchocamera and the like, becausethe brightness of the object and the optical system of the endoscope arevaried depending upon the purposes, thereby requiring a plurality ofelectric power supplying devices for the respective types of theendoscopes, thus resulting in a high cost.

The present invention aims at avoiding the above described disadvantagesof the prior art electric power supplying devices for the endoscopes.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a novel and useful electric power supplying device commonlyusable with endoscopes of the automatic exposure control type and themanual exposure control type.

Another object is to provide a novel and useful electric power supplyingdevice for an endoscope by which an endoscope of the automatic exposurecontrol type can be used as the manual exposure control type byoperating a switch provided in an adapter connecting the endoscope tothe electric power supplying device.

A further object of the present invention is to provide a novel anduseful electric power supplying device commonly usable with differenttypes of endoscopes of the automatic exposure control type.

The above objects are achieved in accordance with the present inventionby the provision of an electric power supply ing device for use with anendoscope having a photographing device, a lamp for illuminating anobject for the observation and a lamp for illuminating the object forthe photographing, the electric power supplying device having anexposure control device, a switching circuit, a voltage adjustableelectric source, a first, a second and a third relay, and a first, asecond and a third electric source for energizing the lamp for theobservation, for energizing the lamp for the photographing and forenergizing the relays, respectively. The first, the second and the thirdrelays are so connected to the electric sources, the switching circuitand the exposure control circuit that, when an endoscope of theautomatic exposure control type having a photoelectric element isconnected to the electric power supplying device through an adapterbelonging to the endoscope to be connected, the photoelectric element isconnected to the exposure control device while the lamp for the phingand the photoelectric element receiving the light of the lamp for thephotographing reflected from the object supplies its output to theexposure control circuit so that, after the lapse of the time determinedtherein in accordance with the intensity of light from the object, theswitching circuit is actuated to terminate the energization of the lampfor the photographing for the proper exposure, while, when an endoscopeof the manual exposure control type is connected to the electric powersupplying device through an adapter belonging to the endoscope to beconnected, the lamp for the observation is energized and, upon actuationof the release means, the second and the third relay are actuated toconnect the voltage adjustable electric source to the exposure controlcircuit so as to supply a reference voltage manually set in the voltageadjustable electric source to the exposure control circuit while thefirst relay is actuated by the third relay to actuate the switchingcircuit so as to energize the lamp for the photographing and, after thelapse of a time period corresponding to the reference voltage manuallyset in the voltage adjustable electric source, the switching circuit isactuated by the exposure control circuit so that the lamp for thephotographing is deenergized for the manually controlled exposure.

In accordance with another feature of the present invention, the adapterof the endoscope of the automatic exposure control type is provided witha switch for permitting the endoscope to be operated as the manualexposure control type. By switching the switch, the second and the thirdrelay are actuated instead of the first relay so that the voltageadjustable electric source is connected to the exposure control circuitin place of the photoelectric element so as to obtain the manualexposure control.

In accordance with a further feature of the present invention, anamplifier is provided in the exposure control circuit in the electricpower supplying device so as to amplify the voltage supplied by thephotoelectric element of the endoscope of the automatic exposure controltype. A variable resistor is connected between the amplifier and theelectric source so that the output of the amplifier is adjustable whenthe input of the amplifier from the photoelectric element so that, byappropriately adjusting the output voltage of the amplifier, differenttypes of films or different types of the endoscopes can be usedinterchangeably with one and the same electric power supplying device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing theelectric connection of the prior art electric power supplying devicewith an endoscope of the automatic exposure control type;

FIG. 2 is a diagram showing an example of the electrical connection ofthe lamps for the observation and for the photographing provided in anendoscope of the manual exposure control type;

FIG. 3 is a diagram similar to FIG. 2 but showing another example of theelectric connection of the lamps in an endoscope of the manual exposurecontrol type;

FIG. 4 is a diagram showing the electric connection of the electricpower supplying device of the present invention with an endoscope of themanual exposure control type shown in FIG. 2;

FIG. 5 is a diagram similar to FIG. 4 but showing the connection withanother kind of the endoscope of the manual exposure control type shownin FIG. 3;

FIG. 6 is a diagram similar to FIG. 4 but showing the connection withthe endoscope of the automatic exposure control type shown in FIG. 1-,

FIG. 7 is a side view showing the adapter for connecting the endoscopeof the automatic exposure control type to the electric power supplyingdevice of the present invention;

connection with the endoscope being simplified for the betterunderstanding of the showing; and

FIG. 10 is a diagram showing the electric connection of the lightintensity control circuit for the lamp for the photographingincorporated in the electric power supplying device of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1showing the prior art electric power supplying device for the endoscopeof the automatic exposure control type having a photoelectric element,the portion at the left side from line X X is the electric powersupplying device connected to the endoscope shown at the right side fromline Y Y in the drawing through an adapter shown in the drawing betweenlines X X and Y Y. The adapter is connected to the endoscope atterminals A A A A A and A while the adapter is connected to the electricpower supplying device at external output terminals E 13,, 5,, E E 15,and E Lamp S for the observation is connected between terminals A and Athrough normally opened main switch 7 coupled with the release means ofthe endoscope and normally closed switch 15 and lamp F for thephotographing is connected between terminals A and A, with terminal Aconnected to terminal A through switch 7, while photoelectric element 13is connected between terminals A, and A,;.

One terminal of electric source 1 for energizing lamp S is connected toterminal E, through variable resistor 4 and the other terminal isconnected to terminal E One terminal of second electric source 3 forenergizing lamp F is connected to terminal E while the other terminal isconnected to terminal E through switching circuit 8 and light intensitycontrol circuit 11. Amplifier 12 is connected to terminals E E andamplifier 12 is connected to integrating circuit which is in turnconnected to voltage detecting circuit 14 for actuating switchingcircuit 8 to disconnect electric source 3 from lamp F when the voltagedetected by detecting circuit 14 reaches a predetermined value. 7

One terminal of third electric source 2 is connected to terminal E,through relay 6 which actuates switching circuit 8 to energize lamp Fwhen relay 6 is energized, while the other terminal is connected toterminal E,.

As shown, terminals A,, A A A A and A are connected to terminals E E E EE, E and E-,, respectively, when the endoscope is connected to theelectric power supplying device through the adapter.

In operation, when the endoscope is connected to the electric powersupplying device through the adapter, lamp S is energized by electricsource I through normally closed switch 15 and variable resistor 4 forthe observation of an object to be inspected By adjusting variableresistor 4, the intensity of light from lamp S is controlled.

When release means (not shown) for operating the photographing device isactuated, normally opened main switch 7 is closed in coupled relation tothe actuation of release means so that relay 6 is actuated by electricsource 2 so as to actuate switching circuit 8 thereby permitting lamp Fto be connected to electric source 3 through switching circuit 8 andlight intensity control circuit 11. Thus, lamp F is energized for thephotographing.

when lamp F is energized, photoelectric element 13 receives the light oflamp F after it is reflected from the object so that an output isgenerated in accordance with the intensity of light received byphotoelectric element 13. The output is amplified by amplifier 12 andsupplied to integrating circuit 10 so as to integrate the input voltageso that voltage detecting circuit 14 supplied with the integratedvoltage from integrating circuit 10 is actuated to actuate switchingcircuit 8 to disconnect electric source 3 from lamp F when theintegrated voltage reaches a predetermined value thereby deenergizinglamp F to terminate the exposure. Since the integrated voltage inintegrating circuit 10 is indicative of the intensity of light receivedby photoelectric element 13, the automatic exposure control is achieved.

Switch 15 is coupled with switch 7 and, when switch 7 is closed incoupled relation to the operation of release means, switch 15 is openedso as to deenergize lamp 5 during the exposure by lamp F.

Light intensity control circuit 11 is so constructed that, when it isactuated, it supplies a high voltage to lamp F for a predetermined timeperiod so as to quickly raise the intensity of light from lamp F to apredetermined intensity and. afier the lapse of a predetermined timeperiod, the voltage is lowered to prevent lamp F from being burnt whilethe predetermined intensity of light is maintained during the exposure.The quick rise of the intensity of light from lamp F is particularlyimportant when the exposure is to be terminated in a very short timeperiod.

However, an endoscope of the manual exposure control type such as shownin FIGS. 2 and 3 cannot be used with the above described prior artelectric power supplying device, because the construction and theelectric connection of the endoscope are different from those of theendoscope of automatic exposure control type as shown in FIG. 1.

In FIG. 2, switch 7' is provided in the circuit of lamp F and, whenrelease means is actuated, the movable contact of switch 7' is connectedto stationary contact 711' to energize lamp F in coupled relation to theoperation of release means while normally closed switch 15 is opened incoupled relation to the operation of release means to deenergize lamp 5.When release means is freed, the movable contact of switch 7 isdisengaged from stationary contact 7a and returned to contact withstationary contact 7b, while switch 15 is closed to energize lamp S.

In FIG. 3, switch 15 is dispensed with so that lamp S is kept energizedduring the time lamp F is energized for the photographing.

FIGS. 4 to 6 show the electric power supplying device of the presentinvention commonly usable with the endoscopes shown in FIGS. 1 to 3,respectively.

FIG. 4 shows the connection of the electric power supplying device withthe endoscope of FIG. 2.

The electric power supplying device of the present invention isgenerally similar to that shown in FIG. 1 except that relay 20 and relay21 and electric source 24 of adjustable voltage are added to thecircuit. One tenninal of relay 20 is connected to the positive terminalof electric source 2 and the other terminal is connected to the movablecontact of contacts 21-1 of relay 21 while one stationary contact ofcontacts 21-1 is connected to terminal E and the other stationarycontact of contacts 21-1 is connected to the negative terminal ofelectric source 2. A capacitor 22 is connected in parallel to relay 20.

One terminal of relay 2! is connected to one stationary contact ofcontacts 20-1 of relay 20 and the other terminal of relay 21 isconnected to the negative terminal of electric source 2. The otherstationary contact of contacts 20-1 is connected to the positiveterminal of electric source 2 while the movable contact of contacts 20-1is connected to one end of capacitor 23 the other end of which isconnected to the negative terminal of electric source 2.

The terminal of relay 6 connected to terminal E, is connected to astationary contact of contacts 21-2 of relay 2l while the movablecontact of contacts 21-2 is connected to the negative terminal ofelectric source 2. Contacts 20-2 of relay are provided between variableresistor 4 and terminal 5,.

One input terminal of amplifier 12 is connected to the movable contactof contacts 20-3 of relay 20 while one of the stationary contacts 20-3is connected to terminal E and the other stationary contact of contacts20-3 is connected to the movable contact of switch in adjustableelectric source 24. Contacts 20-4 of relay 20 are connected in parallelto light intensity control circuit 11.

Terminals 8,, B B of the endoscope are connected to terminals E,, E, andE respectively, by means of the adapter, and terminal B is connected toterminal E in the adapter while terminals E and E are short-circuited bythe adapter.

In operation starting under the condition shown in FIG. 4, capacitor 23is charged through contacts 20-1 and lamp S is energized throughcontacts 20-2 and variable resistor 4. Voltage of adjustable electricsource 24 is adjusted manually by switch 25 in accordance with thecondition of the photographing, i.e., short-distance, medium distance orlong-distance photography so that the adjusted reference voltage can beapplied to amplifier 12 when release means is actuated. Upon actuationof release means for the exposure, switch 7' is switched to stationarycontact 7a so that the current flows from electric source 2, throughrelay 20, the movable contact of contacts 21-1, terminal E terminal 8;,contact 7a, lamp F, tenninal B,, terminal E to electric source 2 so thatrelay 20 is actuated, but the current is insufficient to light lamp F.Upon actuation of relay 20, the movable contact of contacts 20-1 isswitched to relay 21 so that the electric charge of capacitor 23 issupplied to relay 21 to actuate the same. The capacity of capacitor 23is so selected that relay 21 is actuated for a time period longer thanthe exposure time to be manually set by the operator. Upon actuation ofrelay 21, contacts 21-1 are switched so that relay 20 is connecteddirectly to electric source 2 by-passing lamp F so as to be selfl'reldby virtue of contacts 21-1. (This self-holding action is released bymeans (not shown) when release means is freed.) When contacts 21-1 areswitched, the current flowing through relay 20 is instantaneouslyinterrupted. However, capacitor 22 supplies the current to relay 20 sothat the actuation of relay 20 is not affected. Upon actuation of relay20, contacts 20-2 are switched to disconnect lamp 8 from electric source1 to deenergize same and contacts 20-3 are switched to connectadjustable electric source 24 to amplifier 12 so that the manuallyadjusted voltage is applied thereto while contacts 20-4 are closed toshorten the time period during which the high voltage is supplied tolamp F obtained by light intensity control circuit 11 so as to preventlamp F from being burnt during the manual control of the exposure time.

By the switching action of contacts 21-2 upon actuation of relay 21,relay 6 is energized to render switching circuit 8 conductive so thatthe current controlled by light intensity control circuit 1 1 issupplied to lamp F to energize the same for the exposure. The referencevoltage supplied from electric source 24 to amplifier 12 is amplifiedthereby and supplied to integrating circuit 10 thereby permitting theintegrated output voltage of integrating circuit 10 to be detected byvoltage detecting circuit 14.

When the detected voltage in detecting circuit 14 reaches apredetermined value set therein, switching circuit 8 is actuated bydetecting circuit 14 so as to be rendered non-conductive therebydeenergizing lamp F to terminate the exposure after the time period setby the operator by manually adjusting the reference voltage ofadjustable electric circuit 24. When release means is freed, theelectric circuit is returned to the initial condition shown in FIG. 4.

FIG. 5 shows the electric connection of the electric power supplyingdevice of the present invention with the endoscope of FIG. 3. Theactuation of the arrangement of FIG. 5 is similar to that of FIG. 4except that lamp S is not deenergized during the exposure.

FIG. 6 shows the electric connection of the electric power supplyingdevice with the endoscope of the automatic exposure control type shownin FIG. 1.

In this case, tenninals A A A A; and A of the endoscope are connectedthrough adapter 28 shown in FIG. 7 to terminals E E E E and E, of theelectric power supplying device, respectively, and terminal A: isselectively connected by switch 26 in the adapter to terminal E,connected to contact 26a of switch 26 or terminal 5,, connected tocontact 26b of switch 26.

In operation for the automatic exposure control, switch 26 is switchedto contact 260. Then, the operation of the electric power supplyingdevice is the same as that described in connection with FIG. 1, whereinrelays 20, 21 are inoperative and only relay 6 is actuated whileadjustable electric source 24 is disconnected from amplifier 12 andphotoelectric element 13 is connected to amplifier 12.

In operation for the manual exposure control, switch 26 is switched tocontact 26b so that relays 20, 21 are actuated as in the case of theoperation shown in connection with FIGS. 4 and S. In this caseadjustable electric source 24 is also connected to amplifier 12 in placeof photoelectric element 13 by the switching of contacts 20-3 effectedby the actuation of relay 20. The operation is the same as thatdescribed in connection with FIG. 4 or 5.

FIG. 7 shows the adapter to be used in the embodiment of FIG. 6. Adapter28 has a sheath 27 connecting the connector to be connected to theendoscope having switch 26 and the connector to be connected to theelectric power supplying device. Lead wires connecting the matingterminals shown in FIG. 6 extend in sheath 27 and contacts of switch 26are connected to lead wires leading to terminal A terminals E, and Erespectively.

By switching switch 26 to E, the endoscope is operated as the automaticexposure type while it is operated as the manual exposure control typeby switching switch 26 to M.

FIG. 8 shows another embodiment of the present invention in whichvarious kinds of endoscopes of the automatic exposure type and varioustypes of the photosensitive materials are commonly used with the singleelectric power supplying device.

In order to obtain a proper exposure for the film or the photosensitivematerial, the following relations must be satisfied:

Qdr=( /A) H) where:

Q= the intensity of light given to the film A =the sensitivity of thefilm K a constant selected for the proper exposure of the filmTherefore, assuming that the output voltage of the photoelectric elementprovided in the endoscope for receiving the light from the object is V,and k is a constant, when the relation between the output voltage of thephotoelectric element and the intensity of light given to the film isadjusted to satisfy the following equation:

V1 KIQ and a capacitor having the capacity C is charged from zeropotential by the current I proportional to the above voltage V,, thenthe terminal voltage v of the capacitor is represented by the followingequation:

I 2 V1 where k, is a constant, thus the following relation is obtained:

Id! cv (4) From the above equations l (2), (3) and (4),

v g/ (krKlC) (5) Therefore, theproper exposure is obtained when theterminal voltage of the capacitor reaches a value satisfying the aboveequation (5 By varying the constant k, appropriately in accordance withthe various kinds of endoscopes or the various types of thephotosensitive materials, the proper exposure is obtained when theterminal voltage v of the capacitor reaches the same value describedabove.

In FIG. 8, photoelectric element 13 such as a solar battery isselectively connected to amplifier 12 through an adapter not shown)having switch 48 similar to switch 26 shown in FIGS. 6 and 7 foreffecting the automatic exposure control. When switch 48 is switched, anadjustable electric source 49 similar to voltage source 24 in FIGS. 4 to6 is connected to amplifier 12 for the manual exposure control in likemanner as described in connection with FIGS. 4 and 5.

Variable resistor 32 is connected in parallel to photoelectric element13 so that the output voltage V thereof to be supplied to amplifier 12can be adjusted to satisfy the above equation (2) by appropriatelyadjusting variable resistor 32.

The base of transistor 10' of an integrating circuit consisting oftransistor 10' and capacitor 40 is connected to one output terminal ofamplifier 12 while the emitter of transistor 10' is connected to themovable contact of switch 38 capable of being switched to connect to oneend of either of resistors 35, 36 and 37. The opposite ends of resistors35, 36 and 37 are connected to the junction of Zener diode 39 andresistor 46 connected in series to the terminals of electric source 45.The collector of transistor 10' is connected to capacitor 40 and anormally closed switch 41 is connected in parallel to capacitor 40 so asto normally maintain capacitor 40 in deenergized state. Switch 41 isopened in coupled relation to the operation of release means so as tocharge capacitor 40 by electric source 44 connected as shown to energizeamplifier 12, transistor 10', detecting circuit 14 and switching circuit8. Voltage detecting circuit 14 is connected to both ends of capacitor40 so that, when the tenninal voltage of capacitor 40 reaches apredetermined value, detecting circuit 14 is actuated to actuateswitching circuit 8 connected thereto. Switching circuit 8 deenergizesthe lamp for the photographing in like manner as described previously.

In accordance with one feature of the present invention, variableresistor 47 is connected between amplifier 12 and electric source 45, sothat the output voltage a of amplifier 12 appearing when the inputvoltage thereof is zero can be freely adjusted by adjusting variableresistor 47.

Thus, the output voltage V. of amplifier 12 is represented by thefollowing equation:

In o eration for the automatic exposure control after switch 48 isswitched to contact 48a, the output voltage of photoelectric element 13is adjusted by resistor 32 to satisfy the above equation (2) and theadjusted output voltage is applied to amplifier 12. Since the output ofamplifier 12 is connected to the base of transistor 10', the voltage V,V appears at the emitter of transistor 10, where voltage V is thebase-emitter voltage of transistor 10.

By selecting the voltage V, of fixed voltage diode 39 to be z ars. thenthe terminal voltage V of resistor 36, when the same is connected totransistor 10' through switch 38, is represented by the followingequation:

as 2 a+ z (7) By applying the above equation (6) to equation (7),

ss a r+( z im) When variable resistor 47 is adjusted so that the voltageV, V is made zero by adjusting voltage a, then an zr V1 Assuming thatthe resistance of resistor 36 is R then the following relation isobtained:

3 1 36) where I is the current flowing through resistor 36.

This means that current I is proportional to voltage V Since current 1flows through the collector of transistor 10, capacitor 40 is charged bycurrent I when switch 41 is opened in coupled relation to the operationof release means.

When the terminal voltage of capacitor 40 reaches a predetermined value,detecting circuit 14 is actuated to actuate switching circuit 8 todeenergize the lamp for the photographing so as to achieve the properexposure.

If the resistances R R R of resistors 35, 36, 37 are selected to be asas ar then the current I is made greater under the same output voltageV,, whenresistor 35 is connected to transistor 10' by switching switch38 so that the time required to raise the terminal voltage of capacitor40 is made shorter thereby making the exposure time shorter. Whenresistor 37 is connected, the exposure time is made longer. Therefore,the proper exposure is obtained for various types of films or variouskinds of endoscopes by appropriately selecting the resistance of each ofresistors 35, 36, 37.

Since the temperature coefiicient of base-emitter voltage V is inverselyrelated to the temperature coeflicient of voltage V, of fixed Zenerdiode 39, the charging current for capacitor 40 is not influenced by thechange in temperature.

By switching switch 48 to connect adjustable voltage source 49 toamplifier 12, the device can be operated for the manual exposure controlin like manner as previously described.

FIG. 9 shows a further embodiment of the invention in which a safetydevice prevents damage to the photographed object by the excessive heatof the lamp for the photographing when the exposure time is madeexcessively long under the automatic exposure control.

The general arrangement of the device is substantially similar to thosedescribed previously. Photoelectric element 13 supplies its outputindicative of the intensity of light reflected from the object which isilluminated by lamp F for the photographing to amplifier 52 which inturn supplies its output to integrating circuit 53. The voltagedetecting circuit is in the form of a Schmitt circuit consisting oftransistor 60, transistor 61, resistors 55, 56, 57, 58 and 59 connectedas shown and, when switch 67 is closed in coupled relation to theoperation of release means, the voltage of electric source 63 is appliedto the circuit so as to render transistor 61 conductive while transistor60 is made non-conductive so as to integrate the voltage supplied. Whenthe integrated voltage in the circuit reaches a predetermined value,transistors 60, 61 are inverted to render transistor 61 non-conductivewhile transistor 60 is made conductive. Switching circuit 66 isconnected to the output of transistor 61 so that, when transistor 61 ismade conductive, switching circuit 66 is actuated to close switch 68 sothat lamp F is energized by electric source 64. When transistor 60 ismade conductive and transistor 61 is rendered non-conductive, switchingcircuit 66 is actuated to open switch 68 so as to tenninate theenergization of lamp 64 for achieving the proper exposure time.

In accordance with the present invention, transistor 62 is connected inparallel to transistor and variable resistor 54 and capacitor areconnected in series to the terminals of electric source 63 so as to forma timing circuit. The base of transistor 62 is connected to the junctionof resistor 54 and capacitor 65 and normally closed switch 69 isconnected in parallel to capacitor 65 so that capacitor 65 is normallydeenergized. Switch 69 is opened in coupled relation with the closure ofswitch 67.

ln operation, when the intensity of light received by photoelectricelement 13 is low and, hence, the output thereof is very low, a longtime is required for rendering transistor 60 conductive so as todeenergize lamp F which might cause damage to the object. ln such acase, since switch 69 is opened upon actuation of release means tocommence the charging of capacitor 65, the timing circuit consisting ofvariable resistor 54, capacitor 65 and transistor 62 is actuated so asto render transistor 62 conductive when the tenninal voltage ofcapacitor 65 reaches a predetennined value so that the current flowingthrough transistor 61 is switched to How through transistor 62 therebyactuating switching circuit 66 so as to open switch 68 to deenergizelamp F. The time required for raising the terminal voltage of capacitorto the predetermined value is determined by the time constant set by theresistance of variable resistor 54 and the capacity of capacitor 65.Therefore, the time at which lamp F is deenergized is adjusted byadjusting variable resistor 54.

Thus, damage to the object such as a diseased portion of a human bodycan be prevented by the present invention.

FIG. 10 shows a still further embodiment of the present invention bywhich a high voltage is first supplied to the lamp for anode ofthyrister 71. The cathode of thyrister 71 is connected to the otherterminal of the electric source. The cathode of thyrister 75 isconnected to the junction of thyristers 74, 71 while the anode ofthyrister 75 is connected to theother end of lamp 78 through resistor 77and to switch 69' through a resistor 79. Turn-off capacitor 76 isconnected in parallel to resistor 77. The'anode of thyrister 72 isconnected to the anode of thyrister 71 through tum-off capacitor 73 andto one terminal of the electric source through switch 67 and a resistor80, while the cathode of thyrister 72 is connected to the other terminalof the electric source. Stationary contact a of switch 70 is connectedto one end of a resistor 81 the other end of which is connected to theone tenninal of the electric source while the movable contact e ofswitch 70 is connected to one end of a capacitor 82 the other end ofwhich is connected to the other terminal of the electric source andstationary contact b of switch 70 is connected to the gate of thyrister74. The gate of thyrister 72 is connected to the exposure controlcircuit (not shown) such as that previously described. The gate ofthyrister 71 is connected to one output terminal of a conventionalmonostable multivibrator (not shown) incorporated in the electric powersupplying device while the gate of thyrister 75 is connected to theother output terminal of the monostable multivibrator.

in operation, switches 67, 69 are closed in coupled relation with theoperation of release means and, at the same time, switch 70 is switchedto contact b. At the same time or immediately after switch 70 isswitched to contact 11, a signal is applied to the gate of thyrister 71from the one output of the monostable multivibrator so that thyristers74, 71 are rendered operative so as to energize lamp 78 by current notpassing through resistor 77 thus rapidly raising the intensity of lightfrom lamp 78 to a desired intensity. After a predetermined time set bythe monostable multivibrator, a signal is supplied to the gate ofthyrister 75 from the other output terminal of the monostablemultivibrator so that thyrister 74 is rendered inoperative by theprovision of turn-ofi' capacitor 76 so as to apply the voltage of theelectric source through resistor 77 to lamp 78 so that lamp 78 isenergized at the lowered voltage to maintain the desired intensity oflight. After the time determined by the exposure control circuit, asignal is applied to the gate of thyrister 72 thereby renderingthyrister 7| inoperative by the provision of turn-off capacitor 73 todeenergize lamp 78 to achieve the proper exposure.

In accordance with the present invention described above, the intensityof light from the lamp for the photographing is quickly raised so thatextremely short exposure time is available without deteriorating thequality of the photographs while the burning of the lamp is positivelyprevented.

1 claim:

1. in the combination of a photographic endoscope having both manual andautomatic exposure control, said endoscope including at least anobservation lamp and a lamp for illuminating an object to bephotographed and a universal power supply connectable to the endoscope,the power supply comprising:

a first DC source for energizing said observation lamp;

a second DC source for energizing said illuminating lamp;

a first, normally open, switching circuit serially connected in thecircuit between said second DC source and said illuminating lamp;

a first relay means for closing said first switching circuit to energizesaid illuminating lamp;

a manual exposure control circuit for controlling the time intervalduring which said first switching circuit energizes said illuminatinglamp;

a second relay means, actuated by closure of an external pair ofcontacts in the shutter release mechanism of said endoscope, forterminating the energization of said observation lamp and for enablingsaid manual exposure control circuit; and

a third relay means, actuated by the closure of a pair of contactsassociated with said second relay means, for energizing said first relaymeans and for providing a self-holding closure for said second relaymeans, whereby said illuminating lamp is energized for a time perioddetennined by said manual exposure control circuit.

2. In the combination as set forth in claim 1, wherein said endoscopeincludes a photo-electric device for measuring the intensity of lightreflected for the object to be photographed and wherein an automaticexposure control circuit is substituted for said manual exposure controlcircuit, said automatic exposure control circuit comprising:

an amplifier having its input connected to said photoelectric element;

means for adjusting the gain of said amplifier, in the absence of anyinput signal thereto;

a transistor having its base connected to the output of said amplifier;

a resistor in the emitter circuit of said transistor;

a capacitor in the collector circuit of said transistor, the

charge accumulated in said capacitor, by virtue of said resistor, beingproportional to the illumination received by said photo-electricelements;

a pair of normally closed contacts connected acrosssaid capacitor, saidcontacts being coupled to said shutter release, to inhibit charging ofsaid capacitor until said shutter release is actuated; and voltagedetector, having its input connected to said capacitor and its outputconnected to said first switching circuit, said detector having apre-determined threshold such that, as the voltage across said capacitorrises to exceed said threshold, said detector de-activates saidswitching circuit thereby terminating energization of said illuminatinglamp.

3. The universal power supply according to claim 2, further comprising:

an adjustable source of DC potential; and

switching means, connected to the input of said amplifier, forselectively connecting said source of DC potential to said amplifier,whereby the time interval required for the voltage across said capacitorto exceed said threshold is determined by the amplitude of saidadjustable DC potential, to effect manual exposure control.

4. The universal power supply according to claim 1 including anamplifier connected to said photo-electric element;

an integrating circuit connected to the output of said amplifier forintegrating the amplified output voltage from said photo-electricelement;

a Schmitt trigger circuit having its input connected to the output ofsaid integrating circuit, said Schmitt trigger having a predeterminedthreshold voltage;

a switching circuit connected to the output of said Schmitt trigger andincluding means for alternately energizing and de-energizing saidilluminating lamp; and

a timing circuit connected to said Schmitt trigger, said timing circuitincluding:

a transistor;

the serial connection of a capacitor and a variable resistor,

the juncture of said resistor and capacitor being connected to the baseof said transistor; and

a pair of switch contacts connected across said capacitor to inhibitcharge storage therein until said endoscope shutter release isdepressed, said timing circuit returning said Schmitt trigger to itsoriginal state upon expiration of a time interval determined by the timeconstant of said timing circuit.

5. The universal power supply according to claim 1 wherein said manualexposure control circuit comprises:

a source of reference potential;

means for selectively varying the magnitude of said reference potentialin accordance with the exposure desired;

an amplifier connected to said potential varying means;

an integrating circuit, connected to the output of said amplifier, tointegrate the amplified voltage from said reference source;

a voltage detector circuit, having a predetermined threshold, connectedto the output of said integrating circuit, said detector being connectedto said first switching circuit to de-activate same when the output ofsaid integrating circuit exceeds said threshold; and,

means, connected to the input of said amplifier, for selectivelyswitching said amplifier from said source of reference potential to theoutput of a photo-electric cell, in the event said power supply isassociated with an endoscope of the automatic exposure type.

6. The power supply according to claim I, further comprising:

a light intensity control circuit, serially connected with said firstswitching circuit, to apply an initial potential to said illuminatinglamp and, after said lamp is lit, to apply a lesser potential thereto,thereby prolonging the life of said lamp, and minimizing risk of harm tothe object to be photographed.

7. The power supply according to claim 6 wherein said light intensitycontrol circuit comprises:

a first thyristor. serially connected between said illuminating lamp andsaid second DC source;

a second thyristor and a resistor connected in series, across said firstthyristor and providing an alternate path for current flowing throughsaid illuminating lamp;

a first turn-off capacitor interconnecting the anodes of said first andsecond thyristors, in parallel with said resistor; and

a mono-stable multivibrator having a first output connected to thetrigger electrode of said first thyristor to energize same, afterclosure of a contact coupled to said shutter release, to thereby pemtitpassage of a first current through said illuminating lamp, and a secondoutput connected to the trigger electrode of said second thyristor toextinguish said first thyristor, activate said second thyristor, andreduce the current flow through said illuminating lamp by the voltagedrop across said resistor.

8. The power supply according to claim 7 further comprisa thirdthyristor serially connected with said first and second thyristors, thetrigger electrode thereof being connected to the first output of saidmultivibrator;

means for selectively connecting the trigger electrode of said firstthyristor, through a resistor, to one terminal of said second DC source;

a fourth thyristor serially connected with a resistor acros said secondDC source;

a second tum-off capacitor connecting the anodes of said third andfourth thyristors, the trigger electrode of said fourth thyristor beingconnected to the output of said manual exposure control circuit, wherebywhen said exposure control circuit determines that said illuminationlamp has been illuminated for a sufficient time interval, said fourththyristor is triggered on, thereby extinguishing said third thyristor,in turn extinguishing said second thyristor.

1. In the combination of a photographic endoscope having both manual andautomatic exposure control, said endoscope including at least anobservation lamp and a lamp for illuminating an object to bephotographed and a universal power supply connectable to the endoscope,the power supply comprising: a first DC source for energizing saidobservation lamp; a second DC source for energizing said illumiNatinglamp; a first, normally open, switching circuit serially connected inthe circuit between said second DC source and said illuminating lamp; afirst relay means for closing said first switching circuit to energizesaid illuminating lamp; a manual exposure control circuit forcontrolling the time interval during which said first switching circuitenergizes said illuminating lamp; a second relay means, actuated byclosure of an external pair of contacts in the shutter release mechanismof said endoscope, for terminating the energization of said observationlamp and for enabling said manual exposure control circuit; and a thirdrelay means, actuated by the closure of a pair of contacts associatedwith said second relay means, for energizing said first relay means andfor providing a selfholding closure for said second relay means, wherebysaid illuminating lamp is energized for a time period determined by saidmanual exposure control circuit.
 2. In the combination as set forth inclaim 1, wherein said endoscope includes a photo-electric device formeasuring the intensity of light reflected for the object to bephotographed and wherein an automatic exposure control circuit issubstituted for said manual exposure control circuit, said automaticexposure control circuit comprising: an amplifier having its inputconnected to said photoelectric element; means for adjusting the gain ofsaid amplifier, in the absence of any input signal thereto; a transistorhaving its base connected to the output of said amplifier; a resistor inthe emitter circuit of said transistor; a capacitor in the collectorcircuit of said transistor, the charge accumulated in said capacitor, byvirtue of said resistor, being proportional to the illumination receivedby said photo-electric elements; a pair of normally closed contactsconnected across said capacitor, said contacts being coupled to saidshutter release, to inhibit charging of said capacitor until saidshutter release is actuated; and a voltage detector, having its inputconnected to said capacitor and its output connected to said firstswitching circuit, said detector having a pre-determined threshold suchthat, as the voltage across said capacitor rises to exceed saidthreshold, said detector de-activates said switching circuit therebyterminating energization of said illuminating lamp.
 3. The universalpower supply according to claim 2, further comprising: an adjustablesource of DC potential; and switching means, connected to the input ofsaid amplifier, for selectively connecting said source of DC potentialto said amplifier, whereby the time interval required for the voltageacross said capacitor to exceed said threshold is determined by theamplitude of said adjustable DC potential, to effect manual exposurecontrol.
 4. The universal power supply according to claim 1 including anamplifier connected to said photo-electric element; an integratingcircuit connected to the output of said amplifier for integrating theamplified output voltage from said photo-electric element; a Schmitttrigger circuit having its input connected to the output of saidintegrating circuit, said Schmitt trigger having a predeterminedthreshold voltage; a switching circuit connected to the output of saidSchmitt trigger and including means for alternately energizing andde-energizing said illuminating lamp; and a timing circuit connected tosaid Schmitt trigger, said timing circuit including: a transistor; theserial connection of a capacitor and a variable resistor, the junctureof said resistor and capacitor being connected to the base of saidtransistor; and a pair of switch contacts connected across saidcapacitor to inhibit charge storage therein until said endoscope shutterrelease is depressed, said timing circuit returning said Schmitt triggerto its original state upon expiration of a time interval determined bythe time constant of said timing circuit.
 5. The universal power supplyaccording to claim 1 wherein said manual exposure control circuitcomprises: a source of reference potential; means for selectivelyvarying the magnitude of said reference potential in accordance with theexposure desired; an amplifier connected to said potential varyingmeans; an integrating circuit, connected to the output of saidamplifier, to integrate the amplified voltage from said referencesource; a voltage detector circuit, having a predetermined threshold,connected to the output of said integrating circuit, said detector beingconnected to said first switching circuit to de-activate same when theoutput of said integrating circuit exceeds said threshold; and, means,connected to the input of said amplifier, for selectively switching saidamplifier from said source of reference potential to the output of aphoto-electric cell, in the event said power supply is associated withan endoscope of the automatic exposure type.
 6. The power supplyaccording to claim 1, further comprising: a light intensity controlcircuit, serially connected with said first switching circuit, to applyan initial potential to said illuminating lamp and, after said lamp islit, to apply a lesser potential thereto, thereby prolonging the life ofsaid lamp, and minimizing risk of harm to the object to be photographed.7. The power supply according to claim 6 wherein said light intensitycontrol circuit comprises: a first thyristor, serially connected betweensaid illuminating lamp and said second DC source; a second thyristor anda resistor connected in series, across said first thyristor andproviding an alternate path for current flowing through saidilluminating lamp; a first turn-off capacitor interconnecting the anodesof said first and second thyristors, in parallel with said resistor; anda mono-stable multivibrator having a first output connected to thetrigger electrode of said first thyristor to energize same, afterclosure of a contact coupled to said shutter release, to thereby permitpassage of a first current through said illuminating lamp, and a secondoutput connected to the trigger electrode of said second thyristor toextinguish said first thyristor, activate said second thyristor, andreduce the current flow through said illuminating lamp by the voltagedrop across said resistor.
 8. The power supply according to claim 7further comprising: a third thyristor serially connected with said firstand second thyristors, the trigger electrode thereof being connected tothe first output of said multivibrator; means for selectively connectingthe trigger electrode of said first thyristor, through a resistor, toone terminal of said second DC source; a fourth thyristor seriallyconnected with a resistor across said second DC source; a secondturn-off capacitor connecting the anodes of said third and fourththyristors, the trigger electrode of said fourth thyristor beingconnected to the output of said manual exposure control circuit, wherebywhen said exposure control circuit determines that said illuminationlamp has been illuminated for a sufficient time interval, said fourththyristor is triggered on, thereby extinguishing said third thyristor,in turn extinguishing said second thyristor.